There are known image reading devices that convey a medium and reads an image on the conveyed medium. This type of image reading devices include a feed roller and a pressure roller, and a medium is conveyed when the feed roller is rotated while the medium is pressed against the feed roller by the pressure roller.
Japanese Laid-open Patent Publication No. 59-194956 discloses a sheet feeding mechanism that is a simple mechanism capable of feeding sheets including a single sheet and a thick sheet in a certain and accurate manner. Japanese Laid-open Patent Publication No. 2006-312323 discloses a printer in which media may be easily placed and conveyance jam does not occur while the size of the device does not become larger due to an increase in the number of components.
Booklets formed by binding a plurality of pieces of media are thicker than a single medium and therefore it has a problem in entering into a roller nip, which sometimes results in the occurrence of defects during conveyance. Due to the occurrence of defects during conveyance, when an image reading device reads an image on the medium, a defect such as image elongation may occur. When a driven roller is not properly rotated, bend may occur while a booklet is conveyed. Due to the occurrence of bend, it may be difficult for the image reading device to properly read images. When a booklet is conveyed while it is sandwiched between carrier sheets, the image reading device may prevent the occurrence of bend, and images on the booklet may be properly read. Unfortunately, there is a problem of undesirable operability because preparation is needed to sandwich a booklet between carrier sheets.